As a component-to-be-loaded that is aimed for electric contact with a main body apparatus, there is provided a battery pack that is loaded on a video camera.
Such a battery pack can be loaded on a video light, a battery charger and the like other than the video camera, and is in need of aiming for electric contact with these appliances all of which are provided with a terminal of the same form.
Additionally, there are plural-types of batteries based on the difference of capacity and further, as a component-to-be-loaded having a terminal of the same form that is similar to the battery pack, there are, for example, a dry cell pack, a DC plate and the like. By the way, the DC plate is a component-to-be-loaded that has an outer form like the battery pack to be loaded on a battery loading portion, has a cord for connecting to a battery charger and supplies DC electric power to a main body apparatus via this component-to-be-loaded.
Since the main body side apparatus and the component-to-be-loaded are each provided with a terminal of the same form, they are capable of being loaded on each other.
When a dry cell pack is loaded on the battery charger, however, a dry cell ends up being charged by the battery charger, which should be avoided. Moreover, there is a video light dedicated to high capacity that permits loading thereon of only a battery pack with high capacity. A battery pack having low capacity or a battery pack having standard capacity should be avoided from being loaded on such video light dedicated to high capacity.
With regard to a similar component-to-be-loaded with a terminal of the same form, whether or not loading is permitted is determined by the main body side apparatus that is loaded therewith.
As determiners whether or not to permit loading of the similar component-to-be-loaded, the main body side apparatus and the component-to-be-loaded have conventionally been respectively provided with a concave engaging portion and a convex engaging portion, so that the combination of the former and the latter determines whether or not to permit loading of the similar component-to-be-loaded.
However, as mentioned above, in a conventional main body side apparatus and component-to-be-loaded provided with the concave engaging portion and the convex engaging portion, there has been a problem in which terminals of the two are brought into contact with each other while the component-to-be-loaded is in the state of not completely loaded on the main body side apparatus, that is, in the halfway stage of being loaded.
Particularly, when the component-to-be-loaded is forcedly (carelessly) loaded on the main body side apparatus by being tilted slantingly from the regular loading orientation so that both terminals. themselves are opposed to each other, both the terminals ended up being brought into contact with each other.
Then, should a battery pack with different capacity, for example, be loaded on the main body side apparatus, there flows a large amount of current, which incurs the problem such that the main body side apparatus malfunctions and is damaged.
In addition, in recent years, as the main side apparatus has become compact, there is a demand that component-to-be-loaded be also compact. However, when the concave engaging portion and the convex engaging portion are reduced in form and in size as well, the possibility is very high that component-to-be-loaded that should not be capable of being loaded under regular circumstances are erroneously loaded on the main body side apparatus due to changes in form and deformation. In case erroneous loading is committed, there is a high possibility that terminals themselves are brought into contact with each other to thereby incur a problem that leads to some kinds of troubles.